Encoding and decoding of control information for wireless communication

ABSTRACT

Techniques for sending control information in a wireless communication system are described. In one design, a user equipment (UE) may map first information (e.g., CQI information) to M most significant bits (MSBs) of a message and may map second information (e.g., ACK information) to N least significant bits (LSBs) of the message if the second information is sent, where M≧1 and N≧1. The UE may encode the message with a block code, e.g., encode the M MSBs with the first M basis sequences of the block code and encode the N LSBs with the next N basis sequences of the block code. The second information may include N ACK bits. The UE may set each ACK bit to a first value for an ACK or to a second value for a NACK. The second value may also be used for discontinuous transmission (DTX) of ACK information.

The present application claims priority to provisional U.S. ApplicationSer. No. 61/040,700, entitled “DISCONTINUOUS TRANSMISSION DETECTION INJOINT ACKNOWLEDGEMENT AND CHANNEL QUALITY INDICATION TRANSMISSION INPHYSICAL UPLINK CONTROL CHANNEL FOR EXTENDED CYCLIC PREFIX,” filed Mar.30, 2008, assigned to the assignee hereof and incorporated herein byreference.

BACKGROUND

I. Field

The present disclosure relates generally to communication, and morespecifically to techniques for encoding and decoding control informationin a wireless communication system.

II. Background

Wireless communication systems are widely deployed to provide variouscommunication content such as voice, video, packet data, messaging,broadcast, etc. These wireless systems may be multiple-access systemscapable of supporting multiple users by sharing the available systemresources. Examples of such multiple-access systems include CodeDivision Multiple Access (CDMA) systems, Time Division Multiple Access(TDMA) systems, Frequency Division Multiple Access (FDMA) systems,Orthogonal FDMA (OFDMA) systems, and Single-Carrier FDMA (SC-FDMA)systems.

A wireless communication system may include a number of Node Bs that cansupport communication for a number of user equipments (UEs). A Node Bmay transmit data to a UE on the downlink and/or may receive data fromthe UE on the uplink. The downlink (or forward link) refers to thecommunication link from the Node B to the UE, and the uplink (or reverselink) refers to the communication link from the UE to the Node B. The UEmay send channel quality indicator (CQI) information indicative of thedownlink channel quality to the Node B. The Node B may select a ratebased on the CQI information and may send data at the selected rate tothe UE. The UE may send acknowledgement (ACK) information for datareceived from the Node B. The Node B may determine whether to retransmitpending data or to transmit new data to the UE based on the ACKinformation. It is desirable to reliably send and receive ACK and CQIinformation in order to achieve good performance.

SUMMARY

Techniques for sending control information, such as CQI and ACKinformation, in a wireless communication system are described herein. Inan aspect, a transmitter (e.g., a UE) may encode one or more types ofinformation based on a linear block code and may order the differenttypes of information such that a receiver can recover the informationeven in the presence of discontinuous transmission (DTX) of one type ofinformation.

In one design, a UE may map first information (e.g., CQI information) toM most significant bits (MSBs) of a message, where M≧1. The UE may mapsecond information (e.g., ACK information) to N least significant bits(LSBs) of the message if the second information is sent, where N≧1. Themessage may thus include only the first information or both the firstand second information. The UE may encode the message with a block codeto obtain an output bit sequence. In one design, the block code may bederived based on a Reed-Muller code and may comprise multiple basissequences for multiple information bits. The UE may encode the M MSBs ofthe message with the first M basis sequences of the block code. The UEmay encode the N LSBs of the message with the next N basis sequences ofthe block code if the second information is sent.

The second information may comprise N bits for ACK information. In onedesign, the UE may set each bit to a first value (e.g., ‘1’) for an ACKor to a second value (e.g., ‘0’) for a negative acknowledgement (NACK).The second value may also be used for DTX of ACK information. Thisdesign may allow a Node B to detect NACK if the UE misses a downlinktransmission from the Node B and sends DTX for ACK information. The NodeB may then resend data to the UE, which may be the desired response.

Various aspects and features of the disclosure are described in furtherdetail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a wireless communication system.

FIG. 2 shows example transmissions on the downlink and uplink.

FIGS. 3A to 3C show transmission of CQI and ACK information.

FIG. 4 shows a process performed by a UE to send control information.

FIG. 5 shows a process performed by a Node B to receive controlinformation.

FIGS. 6A and 6B show plots of decoding performance.

FIGS. 7 and 10 show two processes for sending control information.

FIG. 8 shows a process for encoding control information.

FIGS. 9 and 11 show two apparatuses for sending control information.

FIGS. 12 and 14 show two processes for receiving control information.

FIGS. 13 and 15 show two apparatuses for receiving control information.

FIG. 16 shows a block diagram of a Node B and a UE.

DETAILED DESCRIPTION

The techniques described herein may be used for various wirelesscommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and othersystems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA system may implement a radiotechnology such as Global System for Mobile Communications (GSM). AnOFDMA system may implement a radio technology such as Evolved UTRA(E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDM®, etc. UTRA and E-UTRA are part ofUniversal Mobile Telecommunication System (UMTS). 3GPP Long TermEvolution (LTE) is an upcoming release of UMTS that uses E-UTRA, whichemploys OFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA,UMTS, LTE and GSM are described in documents from an organization named“3rd Generation Partnership Project” (3GPP). cdma2000 and UMB aredescribed in documents from an organization named “3rd GenerationPartnership Project 2” (3GPP2). The techniques described herein may beused for the systems and radio technologies mentioned above as well asother systems and radio technologies. For clarity, certain aspects ofthe techniques are described below for LTE, and LTE terminology is usedin much of the description below.

FIG. 1 shows a wireless communication system 100, which may be an LTEsystem. System 100 may include a number of Node Bs 110 and other networkentities. A Node B may be a station that communicates with the UEs andmay also be referred to as an evolved Node B (eNB), a base station, anaccess point, etc. UEs 120 may be dispersed throughout the system, andeach UE may be stationary or mobile. A UE may also be referred to as amobile station, a terminal, an access terminal, a subscriber unit, astation, etc. A UE may be a cellular phone, a personal digital assistant(PDA), a wireless modem, a wireless communication device, a handhelddevice, a laptop computer, a cordless phone, a wireless local loop (WLL)station, etc.

The system may support hybrid automatic retransmission (HARQ). For HARQon the downlink, a Node B may send a transmission of data and may sendone or more retransmissions until the data is decoded correctly by arecipient UE, or the maximum number of retransmissions has been sent, orsome other termination condition is encountered. HARQ may improvereliability of data transmission.

FIG. 2 shows example downlink transmission by a Node B and exampleuplink transmission by a UE. The transmission timeline may bepartitioned into units of subframes. Each subframe may have a particularduration, e.g., one millisecond (ms). The UE may periodically estimatethe downlink channel quality for the Node B and may send CQI informationon a physical uplink control channel (PUCCH) to the Node B. In theexample shown in FIG. 2, the UE may send CQI information periodically inevery sixth subframe, e.g., subframes t, t+6, t+12, etc.

The Node B may use the CQI information and/or other information toselect the UE for downlink transmission and to select a suitabletransport format (e.g., a modulation and coding scheme) for the UE. TheNode B may process a transport block in accordance with the selectedtransport format and obtain a codeword. A transport block may also bereferred to as a packet, etc. The Node B may send control information ona physical downlink control channel (PDCCH) and a transmission of thecodeword on a physical downlink shared channel (PDSCH) to the UE insubframe t+4. The control information may comprise the selectedtransport format, the resources used for the data transmission on thePDSCH, and/or other information. The UE may process the PDCCH to obtainthe control information and may process the PDSCH in accordance with thecontrol information to decode the codeword. The UE may generate ACKinformation, which may comprise an ACK if the codeword is decodedcorrectly or a NACK if the codeword is decoded in error. The UE may sendthe ACK information on the PUCCH in subframe t+6. The Node B may send aretransmission of the codeword if a NACK is received and may send atransmission of a new codeword if an ACK is received. FIG. 2 shows anexample in which the ACK information is delayed by two subframes fromthe codeword transmission. The ACK information may also be delayed bysome other amount.

In the example shown in FIG. 2, the Node B may send control informationon the PDCCH and a re/transmission of a codeword on the PDSCH insubframe t+10. The UE may miss the control information sent on the PDCCH(e.g., decode the control information in error) and would then miss thedata transmission sent on the PDSCH. The UE may then send DTX (i.e.,nothing) for ACK information in subframe t+12. The Node B may expect toreceive CQI and ACK information in subframe t+12. The Node B may receiveDTX for the ACK information, interpret the DTX as NACK, and send aretransmission of the codeword.

As shown in FIG. 2, the UE may send CQI and/or ACK information on thePUCCH. The ACK information may convey whether each transport block sentby the Node B to the UE is decoded correctly or in error by the UE. Theamount of ACK information to send by the UE may be dependent on thenumber of transport blocks sent to the UE. In one design, the ACKinformation may comprise one or two ACK bits depending on whether one ortwo transport blocks are sent to the UE. In other designs, the ACKinformation may comprise more ACK bits. The CQI information may conveythe downlink channel quality estimated by the UE for the Node B. The CQIinformation may comprise one or more quantized values for a channelquality metric such as signal-to-noise ratio (SNR),signal-to-noise-and-interference ratio (SINR), etc. The CQI informationmay also comprise one or more transport formats determined based on thechannel quality metric. In any case, the amount of CQI information tosend by the UE may be dependent on various factors such as the number ofspatial channels available for downlink transmission, the format forreporting the downlink channel quality, the desired granularity of thereported downlink channel quality, etc. In one design, the CQIinformation may comprise 4 to 11 bits. In other designs, the CQIinformation may comprise fewer or more bits.

As shown in FIG. 2, the UE may send only CQI information or both CQI andACK information on the PUCCH in a given subframe. The UE may send CQIinformation at a periodic rate and in specific subframes, which may beknown by both the UE and the Node B. The UE may send only CQIinformation when there is no ACK information to send, e.g., in subframet in FIG. 2. The UE may also send only CQI information when the UEmisses the PDCCH and sends DTX for ACK information, e.g., in subframet+12 in FIG. 2. The UE may send both CQI and ACK information when the UEreceives the PDCCH and decodes the PDSCH, e.g., in subframe t+6 in FIG.2. The UE may also send only ACK information, which is not shown in FIG.2.

The UE may encode only CQI information or both CQI and ACK informationin various manners. In general, it may be desirable for the UE to encodeand send only CQI information or both CQI and ACK information such thatthe Node B can reliably receive the information sent by the UE.

In an aspect, the UE may encode only CQI information or both CQI and ACKinformation based on a linear block code. The UE may order the differenttypes of information to send such that the Node B can recover theinformation even in the presence of DTX of one type of information, asdescribed below.

The CQI information may comprise M bits, where M may be any suitablevalue and M≦11 in one design. The ACK information may comprise N bits,where N may also be any suitable value and N≦2 in one design. In onedesign, only CQI information or both CQI and ACK information may beencoded based on a (20, L) block code, which may be derived from a (32,6) Reed-Muller code, where L≧M+N.

In general, an (R, C) Reed-Muller code may be used to encode up to Cinformation bits and generate R code bits. The (R, C) Reed-Muller codemay be defined by an R×C generator matrix G_(R×C) having R rows and Ccolumns. A generator matrix G_(2×2) for a (2, 2) Reed-Muller code withR=2 and C=2 may be given as:

$\begin{matrix}{G_{2 \times 2} = {\begin{bmatrix}1 & 1 \\1 & 0\end{bmatrix}.}} & {{Eq}\mspace{14mu} (1)}\end{matrix}$

A generator matrix G_(2R×C+1) for a (2R, C+1) Reed-Muller code may begiven as:

$\begin{matrix}{{G_{{2R \times C} + 1} = \begin{bmatrix}G_{R \times C} & 1 \\G_{R \times C} & 0\end{bmatrix}},} & {{Eq}\mspace{14mu} (2)}\end{matrix}$

where 1 is an R×1 vector of all ones, and 0 is an R×1 vector of allzeros.

A (32, 6) Reed-Muller code may be defined by a generator matrixG_(32×6), which may be generated based on equations (1) and (2). The 6columns of generator matrix G_(32×6) may be denoted as v₀ through v₅. A(32, 21) second-order Reed-Muller code may be defined by a generatormatrix G_(32×21) containing the six columns of G_(32×6) and 15additional columns generated by linear combination of different possiblepairs of columns of G_(32×6). For example, the seventh column ofG_(32×21) may be generated based on v₀ and v₁, the eighth column may begenerated based on v₀ and v₂, and so on, and the last column may begenerated based on v₄ and v₅.

The (20, L) block code may be obtained by taking 20 rows and L columnsof the (32, 21) second-order Reed-Muller code, where L may be anysuitable value. The (20, L) block code may be defined by a generatormatrix G_(20×L) having 20 rows and L columns. Each column of G_(20×L) isa basis sequence of length 20 and may be used to encode one informationbit. Table 1 shows a generator matrix G_(20×13) for a (20, 13) blockcode for a case in which L=13.

TABLE 1 Basis sequences for (20, 13) block code i M_(i,0) M_(i,1)M_(i,2) M_(i,3) M_(i,4) M_(i,5) M_(i,6) M_(i,7) M_(i,8) M_(i,9) M_(i,10)M_(i,11) M_(i,12)  0 1 1 0 0 0 0 0 0 0 0 1 1 0  1 1 1 1 0 0 0 0 0 0 1 11 0  2 1 0 0 1 0 0 1 0 1 1 1 1 1  3 1 0 1 1 0 0 0 0 1 0 1 1 1  4 1 1 1 10 0 0 1 0 0 1 1 1  5 1 1 0 0 1 0 1 1 1 0 1 1 1  6 1 0 1 0 1 0 1 0 1 1 11 1  7 1 0 0 1 1 0 0 1 1 0 1 1 1  8 1 1 0 1 1 0 0 1 0 1 1 1 1  9 1 0 1 11 0 1 0 0 1 1 1 1 10 1 0 1 0 0 1 1 1 0 1 1 1 1 11 1 1 1 0 0 1 1 0 1 0 11 1 12 1 0 0 1 0 1 0 1 1 1 1 1 1 13 1 1 0 1 0 1 0 1 0 1 1 1 1 14 1 0 0 01 1 0 1 0 0 1 0 1 15 1 1 0 0 1 1 1 1 0 1 1 0 1 16 1 1 1 0 1 1 1 0 0 1 01 1 17 1 0 0 1 1 1 0 0 1 0 0 1 1 18 1 1 0 1 1 1 1 1 0 0 0 0 0 19 1 0 0 00 1 1 0 0 0 0 0 0 bit a₀ a₁ a₂ a₃ a₄ a₅ a₆ a₇ a₈ a₉ a₁₀ a₁₁ a₁₂

A message of K information bits may be defined based on only CQIinformation or both CQI and ACK information. The message may also bereferred to as a word, input data, etc. In one coding design, CQIinformation may be mapped to M MSBs and ACK information may be mapped toN LSBs of the message, as follows:

If only CQI information is sent:

a_(k)=a′_(k) for k=0, . . . , M−1, with K=M, and  Eq (3)

If both CQI and ACK information are sent:

a_(k)=a′_(k) for k=0, . . . , M−1,

a _(k+M) =a′ _(k) for k=0, . . . , N−1, with K=M+N,  Eq (4)

where

a′_(k) is the k-th CQI bit, with k=0, . . . , M−1,

a″_(k) is the k-th ACK bit, with k=0, . . . , N−1, and

a₀ is the MSB and a_(K−1) is the LSB of the message.

The message includes K information bits a₀ through a_(K−1), where K=M ifonly CQI information is sent and K=M+N if both CQI and ACK informationare sent. The K information bits in the message may be encoded with a(20, K) block code as follows:

$\begin{matrix}{{b_{i} = {\sum\limits_{k = 0}^{K - 1}{\left( {a_{k} \cdot M_{i,k}} \right){mod}\; 2}}},\mspace{14mu} {{{for}\mspace{14mu} i} = 0},\ldots \mspace{14mu},19,} & {{Eq}\mspace{14mu} (5)}\end{matrix}$

where b_(i) denotes the i-th code bit and “mod” denotes a modulooperation. The (20, K) block code may be formed with the first K basissequences or columns of the (20, L) block code.

As shown in equation (5), each information bit a_(k) may be encoded bymultiplying a_(k) with each element M_(i,k) of a basis sequence for thatinformation bit to obtain an encoded basis sequence. K encoded basissequences for the K information bits may be combined with modulo-2addition to obtain an output bit sequence (or codeword) composed ofcoded bits b₀ through b₁₉.

For the coding design shown in equations (3) to (5), if only CQIinformation is sent, then M CQI bits may be encoded with a (20, M) blockcode formed by the first M basis sequences of the (20, L) block code. Ifboth CQI and ACK information are sent, then M CQI bits and N ACK bitsmay be encoded with a (20, M+N) block code formed by the first M+N basissequences of the (20, L) block code. The M CQI bits may be encoded withthe first M basis sequences and the N ACK bits may be encoded with thenext N basis sequences of the (20, L) block code.

In one ACK mapping design, an ACK bit may be defined as follows:

$\begin{matrix}{a_{k}^{''} = \left\{ \begin{matrix}1 & {{{ACK}\mspace{14mu} {for}\mspace{14mu} a\mspace{14mu} {transport}\mspace{14mu} {block}}} \\0 & {{{NAK}\mspace{14mu} {for}\mspace{14mu} a\mspace{14mu} {transport}\mspace{14mu} {block}\mspace{14mu} {or}\mspace{14mu} {DTX}}}\end{matrix} \right.} & {{Eq}\mspace{14mu} (6)}\end{matrix}$

where a″_(k) is the k-th ACK bit for the k-th transport block, with k=0,. . . , N−1.

FIG. 3A shows transmission of only CQI information in accordance withthe coding and mapping designs described above. The UE may map M bitsfor CQI information to bits a₀ through a_(M−1) of a message, with a₀being the MSB and a_(M−1) being the LSB. The UE may encode bits a₀through a_(M−1) with the (20, M) block code formed by the first M basissequences of the (20, L) block code and may obtain 20 code bits b₀through b₁₉. The UE may send the code bits on the PUCCH. The Node B mayexpect to receive only CQI information and may decode the PUCCHtransmission in accordance with the (20, M) block code. The Node B mayperform maximum likelihood decoding or may implement some other decodingalgorithm. The Node B may obtain M decoded bits ã₁ through ã_(M−1) andmay interpret these decoded bits as CQI bits.

FIG. 3B shows transmission of both CQI and ACK information in accordancewith the coding and mapping designs described above. The UE may map Mbits for CQI information to bits a₀ through a_(M−1) and may map N bitsfor ACK information to bits a_(M) through a_(M+N−)1 of a message, witha₀ being the MSB and a_(M+N−1) being the LSB. The UE may encode bits a₀through a_(M+N−1) with the (20, M+N) block code formed by the first M+Nbasis sequences of the (20, L) block code and may obtain code bits b₀through b₁₉. The UE may send the code bits on the PUCCH. The Node B mayexpect to receive both CQI and ACK information and may decode the PUCCHtransmission in accordance with the (20, M+N) block code. The Node B mayobtain M+N decoded bits ã₁ through ã_(M+N−1). The Node B may interpretthe first M decoded bits ã₁ through ãM−1 as CQI bits and may interpretthe last N decoded bits ã_(M) through ã_(M+N−1) as ACK bits.

FIG. 3C shows transmission of CQI information and DTX for ACKinformation in accordance with the coding and mapping designs describedabove. The UE may miss the PDCCH and may send only CQI information by(i) mapping M bits for CQI information to bits a₀ through a_(M−1) of amessage and (ii) encoding bits a₀ through a_(M−1) with the (20, M) blockcode, as shown in FIG. 3A. This is equivalent to the UE sending CQIinformation and DTX for ACK information by (i) mapping M bits for CQIinformation to bits a₀ through a_(M−1), (ii) mapping N zeros to bitsa_(M) through a_(M+N−1), and (iii) encoding bits a₀ through a_(M+N−1)with the (20, M+N) block code to obtain code bits b₀ through b₁₉, asshown in FIG. 3C. The code bits b₀ through b₁₉ in FIG. 3C are equal tothe code bits b₀ through b₁₉ in FIG. 3A. The UE may send the code bitson the PUCCH. The Node B may expect to receive both CQI and ACKinformation and may decode the PUCCH transmission in accordance with the(20, M+N) block code. The Node B may obtain M+N decoded bits ã₁ throughã_(M+N−1). The Node B may interpret the first M decoded bits ã₁ throughã_(M−1) as CQI bits and may interpret the last N decoded bits ã_(M)through ã_(M+N−1) as ACK bits. Since the UE sent DTX for the N ACK bits,the Node B would receive NACKs for the ACK bits due to the mapping shownin equation (6).

The coding and mapping designs described above and shown in FIGS. 3A to3C may allow the Node B to correctly recover CQI information andproperly respond to DTX even in a scenario in which the UE misses thePDCCH and transmits only CQI information using the (20, M) block code.In particular, transmitting M CQI bits using the (20, M) block code inFIG. 3A is equivalent to transmitting M CQI bits and N zeros using the(20, M+N) block code in FIG. 3C. The Node B may decode the PUCCHtransmission using the (20, M+N) block code when the Node B expects toreceive both CQI and ACK information and may obtain M+N decoded bits.The Node B may interpret the M decoded MSBs as being for CQI informationand the N decoded LSBs as being for ACK information. If the UE transmitsDTX for ACK information, then the Node B would obtain zeros for the Ndecoded LSBs (assuming correct decoding by the Node B). The Node B mayinterpret these zeros as NACKs and may send a retransmission to the UE,which would be the desired Node B response for the DTX from the UE.

FIG. 4 shows a design of a process 400 performed by the UE for sendingfeedback control information on the PUCCH. The UE may obtain CQIinformation and/or ACK information to send (block 412). The UE maydetermine whether only CQI information is being sent (block 414). If theanswer is ‘Yes’, then the UE may encode M bits of the CQI informationwith the (20, M) block code (block 416) and may send the code bits onthe PUCCH (block 418).

If the answer is ‘No’ for block 414, then the UE may determine whetherboth CQI and ACK information are being sent (block 422). If the answeris ‘Yes’, then the UE may map CQI information to M MSBs and may map ACKinformation to N LSBs of a message (block 424). The UE may then encodethe M MSBs and the N LSBs with the (20, M+N) block code (block 426) andmay send the code bits on the PUCCH (block 428).

If the answer is ‘No’ for block 422, then only ACK information is beingsent. The UE may encode the ACK information (block 432) and may send thecode bits on the PUCCH (block 434).

FIG. 5 shows a design of a process 500 performed by the Node B toreceive feedback control information from the UE. The Node B may receivea transmission on the PUCCH from the UE (block 512). The Node B maydetermine whether only CQI information is expected from the UE (block514). If the answer is ‘Yes’ for block 514, which may be the case if nodata has been sent to the UE, then the Node B may decode the receivedtransmission based on the (20, M) block code to obtain M decoded bits(block 516). The Node B may provide these M decoded bits as M CQI bits(block 518).

If the answer is ‘No’ for block 514, then the Node B may determinewhether both CQI and ACK information are expected from the UE (block522). If the answer is ‘Yes’ for block 522, which may be the case ifdata has been sent to the UE, then the Node B may decode the receivedtransmission based on the (20, M+N) block code to obtain M+N decodedbits (block 524). The Node B may provide the M MSBs of the decoded bitsas M CQI bits (block 526) and may provide the N LSBs of the decoded bitsas N ACK bits (block 528). The Node B may interpret zeros for the ACKbits as NACK/DTX (block 530). If the answer is ‘No’ for block 522, thenthe Node B may decode the received transmission to obtain ACK bits(block 532).

The coding and mapping designs shown in FIGS. 3A to 5 may avoid decodingerrors due to transmission of DTX for ACK information. Decoding errorsmay occur in an alternate design in which ACK information is mapped to NMSBs and CQI information is mapped to M LSBs (which is opposite of thecoding design shown in FIGS. 3A to 3C). In this alternate design, ifonly CQI information is sent, then M CQI bits may be encoded with thefirst M basis sequences of the (20, L) block code. If both CQI and ACKinformation are sent, then N ACK bits may be encoded with the first Nbasis sequences and M CQI bits may be encoded with the next M basissequences of the (20, L) block code. The UE may miss the PDCCH and maysend only CQI information using the (20, M) block code formed by thefirst M basis sequences of the (20, L) block code. The Node B may expectboth CQI and ACK information and may decode based on the (20, N+M) blockcode formed by the first N+M basis sequences of the (20, L) block code.The Node B may obtain N decoded bits for the first N basis sequences andmay interpret these N decoded bits as being for ACK information. TheNode B may obtain M decoded bits for the next M basis sequences and mayinterpret these M decoded bits as being for CQI information. The Node Bmay obtain erroneous ACK information since the N decoded bitsinterpreted as ACK bits are actually N MSBs of the CQI information sentby the UE. The Node B may also obtain erroneous CQI information sincethe M decoded bits interpreted as CQI bits are actually M-N LSBs of theCQI information and N bits of DTX. The design in FIGS. 3A to 5 may avoidthese errors.

Computer simulations were performed to determine decoding performancefor (i) a first mapping scheme with CQI information mapped to MSBs andACK information mapped to LSBs (e.g., as shown in FIG. 3B) and (ii) asecond mapping scheme with ACK information mapped to MSBs and CQIinformation mapped to LSBs (the alternate design). The results of thecomputer simulations are summarized by the following plots.

FIG. 6A shows plots of decoding performance for the first and secondmapping schemes for a scenario with 5 CQI bits and 1 ACK bit using a(20, 6) block code formed with the first six basis sequences of the (20,13) block code. The horizontal axis represents received signal quality,which is given in energy-per-symbol-to-total-noise ratio (Es/Nt). Thevertical axis represents block error rate (BLER). For the first mappingscheme, decoding performance for CQI information is shown by a plot 612,and decoding performance for ACK information is shown by a plot 614. Forthe second mapping scheme, decoding performance for CQI information isshown by a plot 622, and decoding performance for ACK information isshown by a plot 624.

FIG. 6B shows plots of decoding performance for the first and secondmapping schemes for a scenario with 8 CQI bits and 2 ACK bit using a(20, 10) block code formed with the first ten basis sequences of the(20, 13) block code. For the first mapping scheme, decoding performancefor CQI information is shown by a plot 632, and decoding performance forACK information is shown by a plot 634. For the second mapping scheme,decoding performance for CQI information is shown by a plot 642, anddecoding performance for ACK information is shown by a plot 644.

As shown in FIGS. 6A and 6B, similar decoding performance may beobtained for the two mapping schemes. The computer simulations indicatethat mapping the ACK information to LSBs or MSBs provide similardecoding performance using the (20, 13) block code in an additive whiteGaussian noise (AWGN) channel. The computer simulations suggest that the(20, 13) block code provides equivalent protection for all informationbits and that mapping ACK information to either the MSBs or LSBsminimally affect decoding performance.

For clarity, the techniques have been specifically described above for ablock code derived based on a Reed-Muller code. The techniques may alsobe used for other types of block codes such as Reed-Solomon code, etc.

Also for clarity, the techniques have been described above fortransmission of only CQI information or both CQI and ACK information. Ingeneral, the techniques may be used to send first information and secondinformation, each of which may be any type of information. The firstinformation may be mapped to M MSBs, where M≧1. The second informationmay be mapped to N LSBs if it is sent, where N≧1. The M MSBs and the NLSBs may be encoded with a block code comprising a first sub-code forthe M MSBs and a second sub-code for the N LSBs. The first sub-code maybe equal to the block code used to encode only the first information.This may allow a receiver to recover the first information regardless ofwhether it is sent alone or with the second information. The secondinformation may also be defined such that DTX of the second informationwould result in proper action by the receiver.

FIG. 7 shows a design of a process 700 for sending information in acommunication system. Process 700 may be performed by a UE (as describedbelow) or by some other entity. The UE may map first information (e.g.,CQI information) to M MSBs of a message, where M may be one or greater(block 712). The UE may map second information (e.g., ACK information)to N LSBs of the message if the second information is sent, where N maybe one or greater (block 714). The first information may be sent aloneor with the second information in the message. The second informationmay be sent with the first information or not sent in the message. TheUE may encode the message with a block code to obtain an output bitsequence (block 716). The UE may send the output bit sequence on thePUCCH (block 718).

FIG. 8 shows a design of block 716 in FIG. 7. The block code may bederived based on a Reed-Muller code and/or may comprise a plurality ofbasis sequences for a plurality of information bits. The UE may encodethe M MSBs of the message with the first M basis sequences of the blockcode (block 812). The UE may encode the N LSBs of the message with thenext N basis sequences of the block code if the second information issent (block 814).

In one design, if only CQI information is sent, then the message maycomprise M bits and may be encoded with the first M basis sequences ofthe block code. If both CQI and ACK information are sent, then themessage may comprise M plus N bits and may be encoded with the first Mplus N basis sequences of the block code. In one design, the UE may seteach of N ACK bits to a first value (e.g., ‘1’) for an ACK or to asecond value (e.g., ‘0’) for a NACK. The second value may also be usedfor DTX of the ACK information. The ACK information may comprise the NACK bits.

FIG. 9 shows a design of an apparatus 900 for sending information in acommunication system. Apparatus 900 includes a module 912 to map firstinformation to M MSBs of a message, a module 914 to map secondinformation to N LSBs of the message if the second information is sent,a module 916 to encode the message with a block code to obtain an outputbit sequence, and a module 918 to send the output bit sequence on thePUCCH.

FIG. 10 shows a design of a process 1000 for sending information in acommunication system. Process 1000 may be performed by a UE (asdescribed below) or by some other entity. The UE may encode firstinformation (e.g., CQI information) based on a first block code if onlythe first information is sent (block 1012). The UE may encode the firstinformation and second information (e.g., ACK information) based on asecond block code if both the first and second information are sent(block 1014). The second block code may comprise a first sub-code forthe first information and a second sub-code for the second information.The first sub-code may correspond to the first block code. For example,the first block code and the first sub-code may comprise the first Mbasis sequences of a base block code, the second sub-code may comprisethe next N basis sequences of the base block code, and the second blockcode may comprise the first M plus N basis sequences of the base blockcode.

In one design, the UE may set each of N bits to a first value for an ACKor to a second value for a NACK, where N is one or greater. The secondvalue may also be used for DTX of the second information. The secondinformation may comprise the N bits.

FIG. 11 shows a design of an apparatus 1100 for sending information in acommunication system. Apparatus 1100 includes a module 1112 to encodefirst information (e.g., CQI information) based on a first block code ifonly the first information is sent, and a module 1114 to encode thefirst information and second information (e.g., ACK information) basedon a second block code if both the first and second information aresent. The second block code may comprise a first sub-code for the firstinformation and a second sub-code for the second information. The firstsub-code may correspond to the first block code.

FIG. 12 shows a design of a process 1200 for receiving information in acommunication system. Process 1200 may be performed by a Node B (asdescribed below) or by some other entity. The Node B may decode areceived transmission based on a block code to obtain a decoded messagecomprising multiple bits (block 1212). The Node B may provide M MSBs ofthe decoded message as first information (e.g., CQI information), whereM may be one or greater (block 1214). The Node B may provide N LSBs ofthe decoded message as second information (e.g., ACK information), whereN may be one or greater (block 1216). The received transmission maycomprise only the first information or both the first and secondinformation.

The block code may be derived based on a Reed-Muller code and/or maycomprise a plurality of basis sequences for a plurality of informationbits. In one design of block 1216, the Node B may decode the receivedtransmission based on the first M plus N basis sequences of the blockcode to obtain the decoded message. The M MSBs of the decoded messagemay be obtained based on the first M basis sequences of the block code.The N LSBs of the decoded message may be obtained based on the next Nbasis sequences of the block code. In one design, for each bit among theN LSBs of the decoded message, the Node B may provide an ACK if the bithas a first value or a NACK if the bit has a second value. The secondvalue may also be used for DTX of the ACK information.

In one design, the Node B may obtain the received transmission on thePUCCH. The received transmission may comprise a first output bitsequence if only CQI information is sent and may comprise a secondoutput bit sequence if both CQI and ACK information are sent. The firstoutput bit sequence may be obtained by encoding M bits of the CQIinformation with the first M basis sequences of the block code. Thesecond output bit sequence may be obtained by encoding (i) M bits of theCQI information with the first M basis sequences of the block code and(ii) N bits of the ACK information with the next N basis sequences ofthe block code.

FIG. 13 shows a design of an apparatus 1300 for receiving information ina communication system. Apparatus 1300 includes a module 1312 to decodea received transmission based on a block code to obtain a decodedmessage comprising multiple bits, a module 1314 to provide M MSBs of thedecoded message as first information, and a module 1316 to provide NLSBs of the decoded message as second information. The receivedtransmission may comprise only the first information or both the firstand second information.

FIG. 14 shows a design of a process 1400 for receiving information in acommunication system. Process 1400 may be performed by a Node B (asdescribed below) or by some other entity. The Node B may decode areceived transmission based on a first block code if only firstinformation (e.g., CQI information) is expected from the receivedtransmission (block 1412). The Node B may decode the receivedtransmission based on a second block code if both the first informationand second information (e.g., ACK information) are expected from thereceived transmission (block 1414). The second block code may comprise afirst sub-code for the first information and a second sub-code for thesecond information. The first sub-code may correspond to the first blockcode.

In one design, if the second information is expected from the receivedtransmission, then for each of at least one decoded bit for the secondinformation, the Node B may provide an ACK if the bit has a first valueor a NACK if the bit has a second value. The second value may also beused for DTX of the second information.

FIG. 15 shows a design of an apparatus 1500 for receiving information ina communication system. Apparatus 1500 includes a module 1512 to decodea received transmission based on a first block code if only firstinformation (e.g., CQI information) is expected from the receivedtransmission, and a module 1514 to decode the received transmissionbased on a second block code if both the first information and secondinformation (e.g., ACK information) are expected from the receivedtransmission. The second block code may comprise a first sub-code forthe first information and a second sub-code for the second information.The first sub-code may correspond to the first block code.

The modules in FIGS. 9, 11, 13 and 15 may comprise processors,electronics devices, hardware devices, electronics components, logicalcircuits, memories, software codes, firmware codes, etc., or anycombination thereof.

FIG. 16 shows a block diagram of a design of a Node B 110 and a UE 120,which may be one of the Node Bs and one of the UEs in FIG. 1. In thisdesign, Node B 110 is equipped with T antennas 1634 a through 1634 t,and UE 120 is equipped with R antennas 1652 a through 1652 r, where ingeneral T≧1 and R≧1.

At Node B 110, a transmit processor 1620 may receive data for one ormore UEs from a data source 1612, process (e.g., encode, interleave, andmodulate) the data for each UE based on one or more transport formatsselected for that UE, and provide data symbols for all UEs. Transmitprocessor 1620 may also process control information from acontroller/processor 1640 and provide control symbols. A transmit (TX)multiple-input multiple-output (MIMO) processor 1630 may multiplex thedata symbols, the control symbols, and/or pilot symbols. TX MIMOprocessor 1630 may perform spatial processing (e.g., preceding) on themultiplexed symbols, if applicable, and provide T output symbol streamsto T modulators (MODs) 1632 a through 1632 t. Each modulator 1632 mayprocess a respective output symbol stream (e.g., for OFDM) to obtain anoutput sample stream. Each modulator 1632 may further process (e.g.,convert to analog, amplify, filter, and upconvert) the output samplestream to obtain a downlink signal. T downlink signals from modulators1632 a through 1632 t may be transmitted via T antennas 1634 a through1634 t, respectively.

At UE 120, antennas 1652 a through 1652 r may receive the downlinksignals from Node B 110 and provide received signals to demodulators(DEMODs) 1654 a through 1654 r, respectively. Each demodulator 1654 maycondition (e.g., filter, amplify, downconvert, and digitize) arespective received signal to obtain received samples. Each demodulator1654 may further process the received samples (e.g., for OFDM) to obtainreceived symbols. A MIMO detector 1656 may obtain received symbols fromall R demodulators 1654 a through 1654 r, perform MIMO detection on thereceived symbols if applicable, and provide detected symbols. A receiveprocessor 1658 may process (e.g., demodulate, deinterleave, and decode)the detected symbols, provide decoded control information to acontroller/processor 1680, and provide decoded data for UE 120 to a datasink 1660.

On the uplink, at UE 120, data from a data source 1662 and controlinformation (e.g., CQI information, ACK information, etc.) fromcontroller/processor 1680 may be processed by a transmit processor 1664,precoded by a TX MIMO processor 1666 if applicable, conditioned bymodulators 1654 a through 1654 r, and transmitted to Node B 110. At NodeB 110, the uplink signals from UE 120 may be received by antennas 1634,conditioned by demodulators 1632, processed by a MIMO detector 1636 ifapplicable, and further processed by a receive processor 1638 to obtainthe data and control information transmitted by UE 120.

Controllers/processors 1640 and 1680 may direct the operation at Node B110 and UE 120, respectively. Processor 1680 and/or otherprocessors/modules at UE 120 (and also processor 1640 and/or otherprocessors/modules at Node B 110) may perform or direct process 400 inFIG. 4, process 700 in FIG. 7, process 716 in FIG. 8, process 1000 inFIG. 10, and/or other processes for the techniques described herein.Processor 1640 and/or other modules at Node B 110 (and also processor1680 and/or other processors/modules at UE 120) may perform or directprocess 500 in FIG. 5, process 1200 in FIG. 12, process 1400 in FIG. 14,and/or other processes for the techniques described herein. Memories1642 and 1682 may store data and program codes for Node B 110 and UE120, respectively. A scheduler 1644 may schedule UEs for downlink and/oruplink transmission and may provide assignments of resources for thescheduled UEs.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by ageneral purpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

1. A method of sending information in a communication system,comprising: mapping first information to M most significant bits (MSBs)of a message, where M is one or greater; mapping second information to Nleast significant bits (LSBs) of the message if the second informationis sent, where N is one or greater; and encoding the message with ablock code, wherein the first information is sent alone or with thesecond information in the message, and wherein the second information issent with the first information or not sent in the message.
 2. Themethod of claim 1, wherein the block code comprises a plurality of basissequences for a plurality of information bits, and wherein the encodingthe message with the block code comprises encoding the M MSBs of themessage with first M basis sequences of the block code, and encoding theN LSBs of the message with next N basis sequences of the block code ifthe second information is sent.
 3. The method of claim 1, wherein thefirst information comprises channel quality indicator (CQI) informationand the second information comprises acknowledgement (ACK) information.4. The method of claim 1, further comprising: setting each of Nacknowledgement (ACK) bits to a first value for an ACK or to a secondvalue for a negative acknowledgement (NACK), wherein the second value isalso used for discontinuous transmission (DTX) of the ACK information,and wherein the second information comprises the N ACK bits.
 5. Themethod of claim 1, wherein the block code is derived based on aReed-Muller code.
 6. An apparatus for communication, comprising: atleast one processor configured to map first information to M mostsignificant bits (MSBs) of a message, where M is one or greater, to mapsecond information to N least significant bits (LSBs) of the message ifthe second information is sent, where N is one or greater, and to encodethe message with a block code, wherein the first information is sentalone or with the second information in the message, and wherein thesecond information is sent with the first information or not sent in themessage.
 7. The apparatus of claim 6, wherein the block code comprises aplurality of basis sequences for a plurality of information bits, andwherein the at least one processor is configured to encode the M MSBs ofthe message with first M basis sequences of the block code, and toencode the N LSBs of the message with next N basis sequences of theblock code if the second information is sent.
 8. The apparatus of claim6, wherein the at least one processor is configured to set each of Nacknowledgement (ACK) bits to a first value for an ACK or to a secondvalue for a negative acknowledgement (NACK), wherein the second value isalso used for discontinuous transmission (DTX) of the ACK information,and wherein the second information comprises the N ACK bits.
 9. Anapparatus for communication, comprising: means for mapping firstinformation to M most significant bits (MSBs) of a message, where M isone or greater; means for mapping second information to N leastsignificant bits (LSBs) of the message if the second information issent, where N is one or greater; and means for encoding the message witha block code, wherein the first information is sent alone or with thesecond information in the message, and wherein the second information issent with the first information or not sent in the message.
 10. Theapparatus of claim 9, wherein the block code comprises a plurality ofbasis sequences for a plurality of information bits, and wherein themeans for encoding the message with the block code comprises means forencoding the M MSBs of the message with first M basis sequences of theblock code, and means for encoding the N LSBs of the message with next Nbasis sequences of the block code if the second information is sent. 11.The apparatus of claim 9, further comprising: means for setting each ofN acknowledgement (ACK) bits to a first value for an ACK or to a secondvalue for a negative acknowledgement (NACK), wherein the second value isalso used for discontinuous transmission (DTX) of the ACK information,and wherein the second information comprises the N ACK bits.
 12. Acomputer program product, comprising: a computer-readable mediumcomprising: code for causing at least one computer to map firstinformation to M most significant bits (MSBs) of a message, where M isone or greater, code for causing the at least one computer to map secondinformation to N least significant bits (LSBs) of the message if thesecond information is sent, where N is one or greater, and code forcausing the at least one computer to encode the message with a blockcode, wherein the first information is sent alone or with the secondinformation in the message, and wherein the second information is sentwith the first information or not sent in the message.
 13. A method ofsending information in a communication system, comprising: mappingchannel quality indicator (CQI) information to M most significant bits(MSBs) of a message, where M is one or greater; mapping acknowledgement(ACK) information to N least significant bits (LSBs) of the message ifthe ACK information is sent, where N is one or greater; encoding the MMSBs of the message with first M basis sequences of a block code; andencoding the N LSBs of the message with next N basis sequences of theblock code if the ACK information is sent.
 14. The method of claim 13,wherein the message comprises M bits and is encoded with the first Mbasis sequences of the block code if only CQI information is sent, andwherein the message comprises M plus N bits and is encoded with thefirst M plus N basis sequences of the block code if both CQI and ACKinformation are sent.
 15. The method of claim 13, further comprising:setting each of N ACK bits to a first value for an ACK or to a secondvalue for a negative acknowledgement (NACK), wherein the second value isalso used for discontinuous transmission (DTX) of the ACK information,and wherein the ACK information comprises the N ACK bits.
 16. The methodof claim 13, further comprising: obtaining an output bit sequence fromencoding the M MSBs and the N LSBs of the message; and sending theoutput bit sequence on a physical uplink control channel (PUCCH).
 17. Amethod of sending information in a communication system, comprising:encoding first information based on a first block code if only the firstinformation is sent; and encoding the first information and secondinformation based on a second block code if both the first and secondinformation are sent, the second block code comprising a first sub-codefor the first information and a second sub-code for the secondinformation, the first sub-code corresponding to the first block code.18. The method of claim 17, further comprising: setting each of N bitsto a first value for an acknowledgement (ACK) or to a second value for anegative acknowledgement (NACK), where N is one or greater, the secondvalue also being used for discontinuous transmission (DTX) of the secondinformation, and the second information comprising the N bits.
 19. Amethod of receiving information in a communication system, comprising:decoding a received transmission based on a block code to obtain adecoded message comprising multiple bits; providing M most significantbits (MSBs) of the decoded message as first information, where M is oneor greater; and providing N least significant bits (LSBs) of the decodedmessage as second information, where N is one or greater, wherein thereceived transmission comprises only the first information or both thefirst and second information.
 20. The method of claim 19, wherein thedecoding the received transmission comprises decoding the receivedtransmission based on first M plus N basis sequences of the block codeto obtain the decoded message, wherein the M MSBs of the decoded messageare obtained based on the first M basis sequences of the block code, andwherein the N LSBs of the decoded message are obtained based on the nextN basis sequences of the block code.
 21. The method of claim 19, whereinthe first information comprises channel quality indicator (CQI)information and the second information comprises acknowledgement (ACK)information.
 22. The method of claim 19, wherein the block code isderived based on a Reed-Muller code.
 23. An apparatus for communication,comprising: at least one processor configured to decode a receivedtransmission based on a block code to obtain a decoded messagecomprising multiple bits, to provide M most significant bits (MSBs) ofthe decoded message as first information, where M is one or greater, andto provide N least significant bits (LSBs) of the decoded message assecond information, where N is one or greater, wherein the receivedtransmission comprises only the first information or both the first andsecond information.
 24. The apparatus of claim 23, wherein the at leastone processor is configured to decode the received transmission based onfirst M plus N basis sequences of the block code to obtain the decodedmessage, wherein the M MSBs of the decoded message are obtained based onthe first M basis sequences of the block code, and wherein the N LSBs ofthe decoded message are obtained based on the next N basis sequences ofthe block code.
 25. The apparatus of claim 23, wherein for each bitamong the N LSBs of the decoded message, the at least one processor isconfigured to provide an acknowledgement (ACK) if the bit has a firstvalue, and to provide a negative acknowledgement (NACK) if the bit has asecond value, the second value also being used for discontinuoustransmission (DTX) of the ACK information.
 26. A method of receivinginformation in a communication system, comprising: decoding a receivedtransmission based on multiple basis sequences of a block code to obtaina decoded message comprising multiple bits; providing M most significantbits (MSBs) of the decoded message, obtained based on the first M basissequences of the block code, as channel quality indicator (CQI)information, where M is one or greater; and providing N leastsignificant bits (LSBs) of the decoded message, obtained based on thenext N basis sequences of the block code, as acknowledgement (ACK)information, where N is one or greater.
 27. The method of claim 26,wherein the received transmission comprises a first output bit sequenceif only CQI information is sent and comprises a second output bitsequence if both CQI and ACK information are sent, the first output bitsequence being obtained by encoding M bits of the CQI information withthe first M basis sequences of the block code, and the second output bitsequence being obtained by encoding M bits of the CQI information withthe first M basis sequences of the block code and encoding N bits of theACK information with the next N basis sequences of the block code. 28.The method of claim 26, further comprising: for each bit among the NLSBs of the decoded message, providing an ACK if the bit has a firstvalue, and providing a negative acknowledgement (NACK) if the bit has asecond value, the second value also being used for discontinuoustransmission (DTX) of the ACK information.
 29. A method of receivinginformation in a communication system, comprising: decoding a receivedtransmission based on a first block code if only first information isexpected from the received transmission; and decoding the receivedtransmission based on a second block code if both the first informationand second information are expected from the received transmission, thesecond block code comprising a first sub-code for the first informationand a second sub-code for the second information, the first sub-codecorresponding to the first block code.
 30. The method of claim 29,further comprising: if the second information is expected from thereceived transmission, for each bit among at least one decoded bit forthe second information, providing an acknowledgement (ACK) if the bithas a first value, and providing a negative acknowledgement (NACK) ifthe bit has a second value, the second value also being used fordiscontinuous transmission (DTX) of the second information.